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Turbocharger removal: OM668 in W414 — MERCEDES-BENZ

Turbocharger removal — OM668 in W414 on Mercedes-Benz: 168 steps, engines 668.914. What to remove, in what order, and what to check after.

Workshop procedure for MERCEDES-BENZ — the exact step sequence and torque figures, straight from real workshop data.

168 steps 1 engine code

🧭 Before you start

Fits: platform codes 1.7, CDI

  • Opens: fuel
  • Timing position: the crankshaft or camshaft is set and locked during this job

Don't miss

  • Do not drop any timing chain pins into the crankcase

🔧 Engine codes this applies to

668.914

📐 41 workshop diagrams for 668.914

Real factory drawings for this job — timing marks, bolt locations and routing. Locked in the free view.

OM668 in W414 — 668.914 · diagram 1
OM668 in W414 — 668.914 · diagram 2
OM668 in W414 — 668.914 · diagram 3
OM668 in W414 — 668.914 · diagram 4
OM668 in W414 — 668.914 · diagram 5
OM668 in W414 — 668.914 · diagram 6
OM668 in W414 — 668.914 · diagram 7
OM668 in W414 — 668.914 · diagram 8
+ 33 more diagrams
🔒 41 workshop diagrams for this job Ask about your Mercedes-Benz 668.914 — free or sign up free to see the drawings

📋 Procedure

Preparation and removal

  1. Always use new gaskets
  2. Timing chain separating tool:
  3. Disconnect the battery
  4. Timing chain assembly links:
  5. Timing chain assembly tools:
668.914? Steps differ between engine variants — check this job against your exact car before you commit to it. Check my car — free →
  1. Remove the mixing chamber housing with EGR valve
  2. Note: Avoid bending, torsion or traction
  3. Timing chain separating tool:
  4. Extractor:
  5. Disconnect the pressure sensor hose and plug
  6. Remove the oil filler tube
  7. Remove the heat shield(s)
  8. Remove the air inlet plenum
  9. Remove the catalytic converter heat shield(s)
  10. Remove the cooling fan shroud
  11. Disconnect the front exhaust hose from the catalytic converter
  12. Turbocharger:
  13. Disconnect the exhaust clamp
  14. Remove the catalytic converter
  15. Remove the air inlet hose from the turbocharger
  16. Remove the engine lower covers
  17. Remove the noise insulation cover
  18. Disconnect the oil feed and the oil return lines from the turbocharger
  19. Remove the turbocharger heat shield
  20. Disconnect the vacuum hose from the turbocharger actuator
  21. Remove the turbocharger
  22. Disconnect the fuel injector wiring
  23. Disconnect the fuel lines from the injectors
  24. Remove the injection lines
  25. Remove the fuel return line
  26. Remove the fuel injector clamps
  27. Remove the EGR pipe
  28. Remove the injectors
  29. If necessary
  30. Use the special tools
  31. Remove the fuel rail
  32. Disconnect the camshaft position sensor(s)
  33. Remove the turbocharger oil feed line
  34. Remove the glow plug wiring duct
  35. Remove the turbocharger bracket
  36. Remove the high-pressure line(s)
  37. Remove the cylinder head cover
  38. Disconnect the vacuum hose from the vacuum pump
  39. Remove the vacuum pump
  40. Remove the cylinder head front cover
  41. Turn the crankshaft to TDC for cylinder 1
  42. Fit the timing chain holding tool
  43. Note: Remove the cable tie before turning the engine
  44. Secure the chain against the camshaft gearwheel
  45. Note: Use a cable tie
  46. Turn the engine until the chain connecting link shows
  47. Secure the chain against the camshaft gearwheel
  48. Note: Use a cable tie
  49. Disconnect the chain
  50. Remove the assembly link
  51. Remove the camshaft gearwheel
  52. Separate the timing chain
  53. Note: Cover the timing chain housing with a clean cloth
  54. Remove the camshaft cover
  55. Note: Do not drop any timing chain pins into the crankcase
  56. Remove the camshafts

Installation and checks

  1. Connect the ends of the new chain
  2. Remove the timing chain holding tool
  3. Tighten the special tool
  4. Refit the camshaft gearwheel
  5. The timing is correct if:
  6. Pull the removed timing chain pins out of the chain separating tool
  7. Refit the camshaft gearwheel
  8. Fit the camshafts
  9. Chain tensioner:
  10. Refit the cylinder head front cover
  11. Vacuum pump:
  12. Refit the vacuum pump
  13. Reconnect the vacuum hose to the vacuum pump
  14. Cylinder head cover
  15. Refit the cylinder head cover
  16. Refit the high-pressure line(s)
  17. Refit the EGR pipe
  18. Turbocharger bracket bolts
  19. Refit the turbocharger bracket
  20. Refit the glow plug wiring duct
  21. Fit the oil feed line to the turbocharger
  22. Reconnect the camshaft position sensor(s)
  23. Fuel rail:
  24. Refit the fuel rail
  25. Refit the injectors
  26. Refit the fuel injector clamps
  27. Stage 1:
  28. Stage 2:
  29. Stage 3:
  30. Refit the injection lines
  31. Union nut:
  32. Reconnect the fuel lines to the injectors
  33. Reconnect the fuel injector wiring
  34. Refit the turbocharger
  35. Reconnect the vacuum hose to the turbocharger actuator
  36. Refit the turbocharger heat shield
  37. Reconnect the oil feed and oil return lines to the turbocharger
  38. Refit the noise insulation cover
  39. Refit the air inlet hose to the turbocharger
  40. Refit the engine lower covers
  41. Exhaust:
  42. Refit the catalytic converter
  43. Reconnect the exhaust clamp
  44. Reconnect the exhaust pipe to the catalytic converter
  45. Refit the cooling fan shroud
  46. Refit the catalytic converter heat shield(s)
  47. Refit the air inlet plenum
  48. Refit the heat shield(s)
  49. Refit the oil filler tube
  50. Reconnect the inlet manifold vacuum hose
  51. Refit the oil separator
  52. Refit the fuel filter housing
  53. Refit the mixing chamber housing with EGR valve
  54. Refit the air inlet hose
  55. Reconnect the battery
Workshop diagrams

Ask TorqFix about your Mercedes-Benz 668.914 — it answers with the exact sequence for that engine and the workshop drawing for each step. First question is free after a 20-second sign-up, no card.

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Other MERCEDES-BENZ procedures

Who makes these pages, and how

TorqFix was built by a mechanic — after a 2,700 km drive with five roadside repairs that no diagnostic tool could explain.

The figures on this page come from manufacturer workshop documentation and are shown as they are. The page is assembled automatically from that data — it is not written by an AI. The AI works in the chat, where it answers for your specific car. It writes nothing here.

Variants of the same model differ. Cross-check torque against the factory manual for your engine before final tightening.

Seen a figure that does not match your manual? Write to us — we correct it and note when. support@torqfix.com

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Workshop data on this page last updated 20 Sep 2026.